Dryer for automatic car wash equipment

ABSTRACT

Drying apparatus for an automatic car wash having separate sensing means for detecting the proximity of a nozzle to opaque top portions of vehicles and transparent top portions of vehicles to maintain the nozzle within a preselected proximity range of the top portions of the vehicles. Another sensing means is provided to detect the tailgates of open-bed pick-up trucks to retract the nozzle before it hits a tailgate. Also, the means by which the nozzle is mounted and moved toward and away from the vehicles vary the orientation of the nozzle relative to vertical as the nozzles moves between its uppermost and lowermost positions. Similar mounting and moving means can be used with side drying apparatus. In a second and more preferred form, ultrasonic detectors detect both the opaque parts of a vehicle and the windshield.

RELATED APPLICATION

This application is a continuation-in-part of U.S. Pat. No. 4,809,392,issued Mar. 7, 1989.

FIELD OF THE INVENTION

This invention relates to automatic car wash equipment and, inparticular, to a system for drying rinse water from a vehicle by forcedair. More particularly, the invention relates to sensing the proximityof a vehicle and for adjusting the position of a forced air nozzle.

BACKGROUND OF THE INVENTION

It is known to strip rinse water from a vehicle in a car wash. See, forexample, U.S. Pat. Nos. 2,448,834 and 4,161,801. In these two patents,the nozzle through which the forced air is delivered is in contact withthe vehicle surface. While this method takes advantage of the fact thatthe air velocity and pressure are greatest in the immediate vicinity ofthe nozzle, the method is subject to high maintenance costs due to wearand tear on the nozzle.

In U.S. Pat. Nos. 4,587,688 and 4,622,714, the nozzle is maintainedclose to but not in contact with the vehicle surface. In U.S. Pat. No.4,587,688, a sonar-type of proximity detector generates signals whichare sent to a control system which adjusts the position of the nozzleand maintains it in relatively close proximity to the vehicle surface.Such a sonar-type of proximity detector system is, however, limited toangles of incidence up to about 15° , beyond which the reflected signalis not detected.

SUMMARY OF THE INVENTION

A principal object of the present invention is to provide an improvedproximity detection system for a dryer system in an automatic car washequipment.

The foregoing object is accomplished by providing a proximity detectionsystem which, in one preferred form, employs both optic-electronic andalso sonar-type signals. The sonar signals are used to detect thelocation of the windshield. The optic-electronic signals are used todetect the opaque parts of the vehicle, i.e., the hood, roof, deck, sidepanels, etc. The effectiveness of the optic-electronic and sonar-typedetection devices is enhanced by adjusting the angle of the detectiondevices for different portions of the vehicle.

An additional detector is provided to sense the tailgate of an open-bedpick-up truck or similar vehicle to retract the nozzle before it wouldhit the inside of the tailgate.

In a second and more preferred form, the present invention employsultrasonic detectors to detect both the opaque parts of a vehicle andthe windshield.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic illustration of an automatic car wash apparatusembodying the present invention.

FIG. 2 is a side view of a top dryer system constructed in accordancewith the present invention in extended and retracted positions.

FIG. 3 is a top view of a side dryer system constructed in accordancewith the present invention in extended and retracted positions.

FIG. 4 is a schematic circuit diagram of the air/oil control system.

FIG. 5 is a schematic circuit diagram of the electrical control system.

FIG. 6 is a diagrammatic illustration of a second and preferredautomatic car wash apparatus embodying the present invention.

FIG. 7 is a schematic circuit diagram of the electrical control systemfor the FIG. 6 embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates diagrammatically a car wash frame through which a carto be dried travels in the direction indicated by the arrow. Supportedon the frame, at a location immediately following the car rinseoperation, are three dryers: a top dryer, a driver's side dryer and apassenger side dryer. Each of the dryer systems includes a blower havinga slot nozzle through which air is forced at high velocity. The blowersare so mounted as to be movable, as by a pneumatic or hydrauliccylinder, within a limited range to accommodate vehicles of differentwidths and heights.

Movement of the top and side blowers is controlled by a system whichincludes photoelectric sensor switches, control relays, timers, solenoidvalves, flow control valves, hydraulic cylinders, and the like. Movementof the top blower is additionally controlled by an ultrasound detectorpositioned to receive sound wave reflections from the windshield orother top transparent portions (i.e. glass sunroof) of the car. Thephotoelectric and ultrasound sensors are effective to achieve vehiclecontour tracing without any touching of the car surface. The links bywhich the dryers are mounted and moved maintain the proper angle ofattack between the nozzle and the oncoming vehicle.

The car or other vehicle is guided along a guide rail 20 located on thedriver's or left side of the vehicle. This maintains the vehicle at adesired distance from the blower nozzle so that no proximity controlsystem for the driver side blower may be needed. If a proximity controlsystem is needed for the driver side, such system may be essentially thesame as the proximity control system for the passenger side blowersystem, which will be described in detail. Adjustment of the blowernozzle on the passenger side of the vehicle is accomplished by meanswhich include two conventional triple-beam, range-measurementphotoelectric sensor switches PE-3 and PE-4. Adjustment of the topblower nozzle is accomplished by means which include two triple-beam,range-measurement photoelectric sensor switches PE-1 and PE-2 and, inaddition, an ultrasonic sensor US-5. A general description of how thephotoelectric sensor switches operate will first be given.

As shown in FIG. 1, photoelectric switches PE-1 and PE-2 of the topblower system are mounted on the blower nozzle 16 and its beams aredirected toward the approaching vehicle. Each of the photoelectricswitches PE-1 and PE-2 emits a triple beam of pulsated light which isadjustable so that the three beams converge at a predetermined distanceor range from the face of the unit. In the present case, assume thatswitch PE-1 is adjusted so that its three beams converge at a distanceof 14 inches (approximately) from the face of PE-1, and that PE-2 is soadjusted that its beams converge at a distance of 12 inches(approximately) from the face of the unit. The PE units are of thereflective type. Once the range is set, any opaque surface, such as themetal surface of a car or its vinyl roof coming between the rangesetting and the face of the PE unit, will interrupt or break the beamsof light and will reflect light to the receiving section of the PE unit.The PE units may be set for "DARK-ON" or "LIGHT-ON" operation. In thepresent case, it will be assumed that the units are set for "DARK-ON"operation. That is to say, the internal circuit of the PE unit is set sothat its output transistor is ON when no light is being reflected to theunit. Thus, when a car surface reflects light, the internal circuit ofthe PE unit will turn OFF its output transistor.

When a car surface approaches the two units PE-1 and PE-2, and thetriple beams from both PE-1 and PE-2 are broken, the top nozzle 16, onwhich the units PE-1 and PE-2 are mounted, starts to raise until thedistance between the vehicle surface and the faces of PE-1 and PE-2exceeds 12 inches. When this happens, the PE-2 beams are no longerbroken. Nozzle 16 is then held from moving downward until the PE-1 beamsare no longer broken. It should be pointed out that photoelectric unitsPE-1 and PE-2 are mounted on top nozzle 16 at a fixed distancerearwardly (upwardly) from the orifice. Assume this distance to be about6 inches. Thus, when it is said that the nozzle 16 is moved by theproximity detection system to maintain the distance between the face ofthe photoelectric units PE-1, PE-2 and the car surface within a range of12-14 inches, the nozzle is actually being maintained within thetwo-inch range of 6-8 inches (12-14 minus 6) from the surface of thevehicle.

Also shown in FIG. 1 is tailgate sensor PE-6. When an open-bed pick-uptruck or similar vehicle is being dried, nozzle 16 can hit the insidesurface of the tailgate because none of the sensors PE-1, PE-2 or US-5is arranged to detect such a vertical surface. The problem is compoundedby the tendency of certain drivers to pull-out of a car wash quickly asthey pass the dryers leaving inadequate time for the top nozzle toretract from the open bed.

Sensor PE-6 is a photoelectric sensor which is disposed with asubstantially horizontal orientation and, therefore, can detect verticalsurfaces. When an open-bed pick-up truck is being dried, nozzle 16 willdrop into the open bed. Sensor PE-6 will detect the tailgate and causenozzle 16 to be retracted to a height which clears the tailgate beforethe nozzle hits the tailgate.

In FIG. 2, top blower 15 and nozzle 16 are shown in solid lines for theuppermost position of the nozzle and by phantom lines for the lower mostposition of the nozzle. Actuation of cylinder 46 causes nozzle 16 tomove. As the rod of cylinder 46 extends, member 21, mounted for pivotalmovement about pivot 22 and connected to nozzle 16 through arm 23, movesnozzle 16 upward. Arm 23 is connected to nozzle 16 for pivotal movementabout pivot 24. Arm 23 is fixed rigidly to member 21. A second arm 25 isconnected to nozzle 16 for pivotal movement about pivot 26 with theopposite end of arm 25 mounted for pivotal movement about pivot 27.

The distance between pivot 24 and pivot 26 is greater than the distancebetween pivot 22 and pivot 27. The length of arm 25 is equal to thelinear distance between pivot 22 and pivot 24. This relationship of thepivots results in the orientation of the nozzle changing as the nozzlemoves between its uppermost and lowermost positions. As an example, thearrangement shown in FIG. 2 can vary the nozzle orientation from between15° to 20° from the vertical with the nozzle in its lowermost positionand 5° to 71/2° from the vertical with the nozzle in its uppermostposition. In this way, the nozzle orientation is adjusted for differenttop portions of the vehicle being dried. When the nozzle is over thehood, it is lower than when it is over the roof. Generally, the hood issloped slightly upward toward the front windshield, while the roof ishorizontal. With the orientation of the nozzle changing as it movesbetween its lowermost and uppermost positions, the air leaving thenozzle hits the hood and the roof portions of the vehicle at generallythe same angle. In addition, this enhances the detection of the vehiclesurfaces by operating the sensors near the centers of their angularranges.

It will be noted that the range over which the nozzle orientationchanges is relatively small and corresponds generally to the typicalslope of the hood. The arrangement shown in FIG. 2 is effective inproducing the relatively small changes in nozzle orientation formovement of the nozzle between its uppermost and lowermost positions.

The action of the photoelectric sensor switches PE-3 and PE-4 associatedwith the passenger side of the vehicle is similar to that describedabove for the top portion sensors. Of course, instead of raising theside nozzle, when the triple beams of PE-3 and PE-4 are both broken, theside proximity detector system causes side nozzle 17 to retract. In thecase of the top dryer system, the nozzle 16 is lowered to the lowermostposition by gravitational force. In the case of the side dryer system14, the nozzle 17 is extended toward the car path by the application ofpneumatic force. A linkage system, similar to the one shown in FIG. 2,can be used to support and move nozzle 17.

The side photoelectric switch units PE-3 and PE-4 may be assumed to beset to converge at 18 inches and 22 inches, respectively, thusestablishing a 4-inch range within which the side nozzle is maintained.Assuming that the photoelectric units PE-3 and PE-4 are mounted on sidenozzle about 6 inches from the orifice, the passenger side proximitydetector system 14 maintains the nozzle 17 within a 4-inch range of12-16 inches (18-22 minus 6) from the passenger side surface.

Referring again to the top dryer system 15, as already indicated, thetop system includes an ultrasound detector unit, US-5; such as ShermanIndustries, Inc. Sonar Sensor 5750-060. Such a unit is necessary becausephotoelectric units, such as PE-1 and PE-2, have difficulty in detectingand responding to light permeable surfaces, such as the glasswindshield. For this reason, the top dryer system includes ultrasonicunit US-5 which is positioned to detect and respond to the windshield ofthe vehicle. The unit US-5 is mounted on the top nozzle 16 and may beset to have a range of 10 inches. When a reflected ultrasound signal isdetected, the top nozzle 16 is raised. In most automobiles, thewindshield is positioned at an angle of between 22° and 27° from thevertical. Hence, unit US-5 may be set at an angle about mid-way between22° and 27°. With respect to other glass surfaces of the automobilewhich are substantially perpendicular to the ground (or in some casesparallel to the ground), the ultrasonic unit US-5 produces no signalfrom such surfaces since the US-5 unit only responds to reflections whenthe angle of incidence is less than about 15°. When the ultrasonic unitUS-5 detects the windshield, it is effective to lift the nozzle 16irrespective of the state of PE-1 and PE-2. In other words, US-5 isdesigned to override PE-1 and PE-2. Similarly, tailgate sensor PE-6 iseffective to override PE-1 and PE-2. When photoelectric sensor PE-6detects a tailgate, it will cause nozzle 16 to be raised irrespective ofthe state of sensor PE-1 or sensor PE-2.

On the basis of the description given thus far, the photoelectricsystems would control the positions of nozzles 16 and 17 by subjectingthe nozzles to oscillatory movement. To avoid such oscillations, timedelays are introduced into the system. For example, a time delay of twoseconds is introduced by a timer relay to maintain top nozzle 16 forthat period of time in its raised, lowered or holding state and, in thecase of side nozzle 17, to maintain side nozzle 17 for two seconds inits retracted, extended or holding state.

Movement of nozzles 16 and 17 is accomplished by piston cylinders 46 and60, respectively (FIGS. 2, 3 and 4). These cylinders are actuated andcontrolled by an pneumatic/hydraulic control system 30 shownschematically in FIG. 4 and now to be described.

In system 30, a compressed air source 62 supplies air (about 80-100p.s.i.) by way of air line 31 through a normally-open solenoid valve 32to an air/oil reservoir 38. Reservoir 38 is effective, in response toair pressure from line 31, to provide hydraulic pressure to line 45which is connected to an oil solenoid valve 40. Solenoid valve 40 iscontrolled by electrical signals supplied to its coil 40a. The positionof the spool in valve 40 is controlled by air pressure in line 31a. Whenno electrical current is supplied to coil 40a, valve 40 is normally openand hydraulic pressure is applied through valve 40, oil line 45aflow-control valves 42, 44 to the left side of the piston of hydrauliccylinder 46. This is the condition illustrated in FIG. 4. This pressuremaintains the piston of cylinder 46 fully extended and maintains topnozzle 16 in its uppermost, fully raised position. This is the fail-safeposition. In other words, in the event of loss of electrical power,nozzle 16 is maintained in its raised position.

Nozzle 16 is also moved to its raised position in response to the triplebeams of both PE-1 and PE-2 being broken by a car surface and lightbeing reflected to the PE units. This is the LIGHT-ON condition of theunits. In this condition, the output transistor is OFF and no currentflows through solenoid coils 32a, 40a.

When the system is operating and light is not being reflected to bothPE-1 and PE-2, coils 40a and 32a are energized and air pressure isexhausted through solenoid valve 32. This allows the oil pressure atunit 38 and at oil solenoid valve 40 to drop and allows oil to flowthrough flow control valves 44, 42. This allows the piston of cylinder46 to move from right to left in response to gravitational force onnozzle 16. Thus, nozzle 16 moves down to its lowermost position awaitingarrival of a car.

When a car surface comes within 12 inches of the units PE-1 and PE-2,the triple beams of both units are broken, light is reflected to bothunits, and both units turn OFF. This deenergizes coil 40a of valve 40and coil 32a of valve 32. This puts both of the valves 40 and 32 in theconditions illustrated in FIG. 4. Air pressure from line 31 is appliedto air/oil reservoir 38 and oil pressure is applied through oil lines45, 45a and flow control valves 42, 40 to the left end of hydrauliccylinder 46, causing its piston to extend and causing the nozzle 16 tobe raised. This action continues until the distance between the carsurface and the units PE-1 and PE-2 are no longer broken. Nozzle 16 isthen held.

The air/oil control system for the passenger side nozzle 17 is alsoshown in FIG. 4 and operates in a generally similar manner to that justdescribed, except that gravity plays no role in its operation. Airpressure in line 31 is applied through the normally-open solenoid valve50 into air-oil reservoir 52. In response to such air pressure,hydraulic pressure is applied through normally-open solenoid valve 54,oil line 55a, and flow-control valves 56, 58 into the left side of thepiston in hydraulic/pneumatic cylinder 60. This causes the piston ofcylinder 60 to retract and puts side nozzle 17 at its most outwardposition. This is the fail-safe condition in that, in the event of lossof electrical power, with coils 50a and 54a deenergized, the solenoids50 and 54 are in the conditions illustrated in FIG. 4 and the nozzle 17is in its retracted position.

Since nozzle 17 on the passenger side of the car is not affected bygravity, in order to extend nozzle 17 it is necessary to apply airpressure to the right side of the piston of hydraulic/pneumatic cylinder60, and this is done by way of air line 66, which carries air at lesspressure than air line 31. However, air valve 50 and oil valve 54 areboth normally open and hydraulic pressure is normally applied to theleft side of the piston of cylinder 60. This is effective to retract thepiston against the reduced air pressure applied through line 66 by wayof pressure-reducing valve 64b. Forty (40) pounds of air pressure(p.s.i.) may, for example, be applied through line 66 to the right sideof the piston of cylinder 60.

With nozzle 17 retracted, when the system is turned on, with no lightbeing reflected to PE units PE-3 and PE-4, coils 50a and 54a areenergized. This causes air solenoid valve 50 to move to the ventposition and causes hydraulic valve 54 to move to the closed position.This reduces the pressure in oil lines 55 and 55a and allows the 40 lbs.of air pressure, which is being applied to the right side of thecylinder, to move the piston from right to left, thereby extending thepiston and moving nozzle 17 toward the car path. When an opaque carsurface comes within 18 inches of the faces of units PE-3, PE-4, thetriple beams of both photoelectric switches are broken, light isreflected to both units, the units turn OFF, coils 50a and 54a aredeenergized and the solenoid valves 50 and 54 return to the positionillustrated in FIG. 4.

The opto-electronic portion of the control system will now be described.A schematic of the optoelectric circuitry is shown in FIG. 5 to whichreference will now be made. As already indicated, the photoelectricsensor switches PE-1, PE-2, PE-3 and PE-4 are ON when their respectivebeams are not interrupted and are OFF when their beams are broken andlight is reflected to the units. As also described, each PE unit emits atriple-beam of light which is focused at a selected distance from theface of the PE unit. In the present case, it has been assumed thatswitch PE-1 which functions as the TOP HOLD sensor switch is focused at14 inches, that switch PE-2 which functions as the TOP RAISE sensorswitch is focused at 12 inches, that switch PE-3 which functions as theSIDE HOLD sensor is focused at 22 inches, and that switch PE-4 whichfunctions as the SIDE RETRACT sensor switch is focused at 18 inches. Ithas also been assumed that each of the PE units is mounted on the nozzlestructure 6 inches away from the orifice of the nozzle. Thus, thenozzles of the top and passenger side blowers are 6 inches closer to theautomobile surface than are the focal dimensions given above.

As seen in FIG. 5, when the triple beams of PE-1 alone are broken by acar surface, the coil of relay 1-CR is deenergized and its contacts inbranch 83, which had been closed, now open. Nothing happens, however,since the contacts of relay 2-CR in branches 81, 82 are still closed.When the triple beams of PE-2 are also broken, the coil of relay 2-CR isdeenergized and its contacts in branches 81, 82 now open. Thisdeenergizes winding 40a of solenoid valve 40 (FIG. 4) and moves thevalve to the open position illustrated in FIG. 4. Oil pressure is nowapplied to the left end of cylinder 46 and nozzle 16 is raised towardthe UP position. As soon as the distance between the car surface and theface of PE-2 exceeds 12 inches, the beams of PE-2 are no longerreflected to the PE-2 cell and PE-2 turns ON. This energizes the coil ofrelay 2-CR and its contacts in branches 81, 82 close. This energizescoil 40a and moves solenoid valve 40 to the closed or blocking position,thereby holding nozzle 16. If the distance between the face of the PEunits and the car surface should exceed 14 inches, the triple beam ofPE-1 will also not be broken, no light will be reflected to PE-1 andPE-1 will turn ON. Relay coil 1-CR will now be energized and itscontacts 1-CR in branch 83 will close. This energizes the coil of timerrelay 1-TR and, after a delay of two seconds, the 1-TR contacts inbranch 81 will open. This deenergizes the coil 32a of solenoid valve 32and moves valve 32 to the closed position. However, during thetwo-second delay, the valve 32 was in exhaust condition. This allowedthe oil pressure in lines 45a and 45 to be reduced and allowed thepiston in cylinder 46 to move in a direction to lower nozzle 16.

The action of the proximity detector and control system for the topdryer system may be summarized as follows. As the distance from thephotoelectric switch units PE-1 and PE-2 to the car surface decreases,either because the car is approaching the units and/or because the topnozzle 16 on which the PE-1 and PE-2 units are mounted is droppingdownwardly, when the distance becomes less than 14 inches, the triplebeams of PE-1 are broken. When the distance becomes less than 12 inches,the triple beams of PE-2 are also broken. When the beams of both PE-1and PE-2 are broken, the control system raises nozzle 16 until thedistance exceeds 12 inches. The nozzle 16 is then HELD, but only so longas the distance does not exceed 14 inches. If the distance exceeds 14inches, nozzle 16 is allowed to drop downwardly by gravity until thedistance is between 12" and 14", at which time the nozzle is held atthis distance. Timer delay relays are used to avoid or reduceoscillatory movement. Top nozzle 16 is maintained by the photoelectricand air/oil circuitry of FIGS. 4 and 5 within a 12-14 inch range. Aspreviously indicated, this is the distance from the reflecting surfaceof the car to the face of the PE-1 and PE-2 photoelectric switches.However, since these cells are mounted on the blower-nozzle structureapproximately 6 inches above the orifice of the nozzle 16. Thus, therange in which nozzle 16 is maintained is actually 6-8 inches from thecar.

The side photoelectric switch units PE-3 and PE-4 function in agenerally similar manner to that just described. As indicatedpreviously, the side system differs from the top system in that gravityplays no part. Retraction of the piston of hydraulic cylinder 60 iseffected by air pressure applied through line 66 to the right side ofthe piston.

For the convenience of the reader, Table 1 and 2 are presented below.Table 1 relates to the top nozzle 16. Table 2 relates to the passengerside nozzle 17. These two Tables present in summary form the action orcondition of the top and side nozzles 16, 17 under the variousconditions of the beams of PE-1, PE-2, PE-3 and PE-4, i.e., beams brokenor unbroken by the surface of the car.

                  TABLE 1                                                         ______________________________________                                        PE-1         PE-2      Top Nozzle 16                                          ______________________________________                                        Broken       Broken    Raise                                                  Broken       Unbroken  Hold                                                   Unbroken     Unbroken  Lower                                                  ______________________________________                                    

                  TABLE 2                                                         ______________________________________                                        PE-3         PE-4      Side Nozzle 17                                         ______________________________________                                        Broken       Broken    Retract                                                Broken       Unbroken  Hold                                                   Unbroken     Unbroken  Extend                                                 ______________________________________                                    

The Tables given above do not include the ultrasound detector US-5 whichis mounted on the top nozzle 16. This detector causes the top nozzle 16to raise when sound is reflected to the detector from a windshield whichhas come within 10 inches of the detector. As seen in FIG. 5, when US-5is actuated by a reflected ultrasound signal, the coil of relay 5-CR isenergized and its normally-closed contacts 5-CR now open. Thisdeenergizes the coil of relay 2-CR and its contacts 2-CR in branch 82open. This deenergizes winding 40a of solenoid valve 40 and puts valve40 in the condition shown in FIG. 4. Oil pressure is applied to the leftend of cylinder 46 and nozzle 16 is raised.

The Tables given above also do not include photoelectric sensor PE-6.This sensor controls movement of nozzle 16 in much the same way asultrasound sensor US-5. Sensor PE-6 differs from sensors PE-1, PE-2,PE-3 and PE-4 because sensor PE-6 is OFF when its beam is uninterruptedand ON when its beam is broken. When an object is in close proximity tosensor PE-6 and interrupts its beam, the coil of relay 6-CR is energizedand its normally closed contacts now open. This deenergizes the coil ofrelay 2-CR and its contacts in branch 82 open. This deenergizes the coilof relay 2-CR and its contacts in branch 82 open. This deenergizeswinding 40a of solenoid valve 40 and puts solenoid valve 40 in thecondition shown in FIG. 4. Oil pressure is applied to the left end ofcylinder 46 and nozzle 16 is raised.

The triple beam photoelectric sensor switches which have been identifiedin this application as units PE-1, PE-2, PE-3, PE-4 and PE-6 maypreferably be photoelectric switches (area reflection type) such asSherman Industries, Inc. Triple Beam Photosensors 5750-030. The unitsmay be connected to operate when light enters (LIGHT-ON) or may beconnected to operate when light is blocked (DARK-ON). In the systemwhich has been described above, the PE-1, PE-2, PE-3 and PE-4 switchesare assumed to be connected to operate when light is blocked (DARK-ON),and the PE-6 switch is assumed to be connected to operate when the beamis uninterrupted (LIGHT-ON).

In the FIG. 6 embodiment of the invention, adjustment of the top blowernozzle is accomplished by means which include two range-measurementultrasonic sensor switches US-7 and US-8. Each of these ultrasonicsensors may be, for example, a product of Migatron Corp., Part No.RPS-100-72, having an angular range of approximately 35° to each side ofthe perpendicular to a surface being detected. As will be understoodfrom the following explanation, such ultrasonic sensors can function todetect both opaque and transparent surfaces with the result that twosuch sensors can replace sensors PE-1, PE-2 and US-5 making theembodiment of FIG. 6 preferred.

As shown in FIG. 6, ultrasonic switches US-7 and US-8 of the top blowersystem are mounted on the blower nozzle 16 and they are directed towardthe approaching vehicle. Each of the ultrasonic switches US-7 and US-8:(1) transmits ultrasonic pulses toward a target, (2) receivesreflections from the target, and (3) develops outputs which control themovement and positioning of the top blower system determined by the timerequired for the ultrasonic pulses to make the round-trip from thesensors to the target and back to the sensors. Each of the ultrasonicsensors is set for a different round-trip time, so that the outputs ofthe sensors locate the surface to be detected relative to the sensors.In the present case, assume that switch US-7 is adjusted so that itsignals when a vehicle is within a distance of 14 inches (approximately)from the face of US-7, and that US-8 is adjusted so that it signals whena vehicle is within a distance of 12 inches (approximately) from theface of US-8. Once the range is set, any surface, such as the metalsurface of a car or its vinyl roof or glass windshields or sunroofs,coming between the range setting and the face of the ultrasonic unit,will cause the sensor to generate an appropriate output.

When a car surface approaches the two units US-7 and US-8, and comeswithin 12 inches from both US-7 and US-8, the top nozzle 16, on whichthe units US-7 and US-8 are mounted, starts to raise until the distancebetween the vehicle surface and the faces of US-7 and US-8 exceeds 12inches. When this happens, the output of sensor US-8 changes. Nozzle 16is then held from moving downward until the output from sensor US-7changes. It should be pointed out that ultrasonic units US-7 and US-8are mounted on top nozzle 16 at a fixed distance rearwardly (upwardly)from the orifice. Assume this distance to be about 6 inches. Thus, whenit is said that the nozzle 16 is moved by the proximity detection systemto maintain the distance between the face of the ultrasonic units US-7,US-8 and the car surface within a range of 12-14 inches, the nozzle isactually being maintained within the two-inch range of 6-8 inches (12-14minus 6) from the surface of the vehicle.

Nozzle 16 is moved to its raised position in response to the outputs ofboth US-7 and US-8 when a car surface comes within range. When thisoccurs, the outputs of the sensors are OFF and no current flows throughsolenoid coils 32a, 40a.

When the system is operating and a vehicle is not within range, so thatneither ultrasonic sensor detects a vehicle surface, coils 40a and 32aare energized and air pressure is exhausted through solenoid valve 32.This allows the oil pressure at unit 38 and at oil solenoid valve 40 todrop and allows oil to flow through flow control valves 44, 42. Thisallows the piston of cylinder 46 to move from right to left in responseto gravitational force on nozzle 16. Thus, nozzle 16 moves down to itslowermost position awaiting arrival of a car.

When a car surface comes within 12 inches of the units US-7 and US-8,both units turn OFF. This deenergizes coil 40a of valve 40 and coil 32aof valve 32. This puts both of the valves 40 and 32 in the conditionsillustrated in FIG. 4. Air pressure from line 31 is applied through oillines 45, 45a and flow control valves 42, 40 to the left end ofhydraulic cylinder 46, causing its piston to extend and causing thenozzle 16 to be raised. This action continues until the distance betweenthe car surface and the sensors US-7 and US-8 exceeds the specifieddistance namely, 14 inches. Nozzle 16 is then held.

The electrical control system of FIG. 7 will now be described. Asalready indicated, the ultrasonic sensor switches US-7 and US-8 and thephotoelectric sensor switches PE-3 and PE-4 are ON when a vehicle is outof range and are OFF when a vehicle is within range. In the presentcase, it has been assumed that sensor switch US-7 which functions as theTOP HOLD sensor switch is set at 14 inches, that switch US-8 whichfunctions as the TOP RAISE sensor switch is set at 12 inches, thatswitch PE-3 which functions as the SIDE HOLD sensor is focused at 22inches, and that switch PE-4 which functions as the SIDE RETRACT sensorswitch is focused at 18 inches. It has also been assumed that each ofthe sensor units is mounted on the nozzle structure 6 inches away fromthe orifice of the nozzle. Thus, the nozzles of the top and passengerside blowers are 6 inches closer to the automobile surface than are thedimensions given above.

As seen in FIGS. 5 and 7, when the ultrasonic sensor US-7 alone is OFF,the coil of relay 1-CR is deenergized and its contacts in branch 83,which had been closed, now open. Nothing happens, however, since thecontacts of relay 2-CR in branches 81, 82 are still closed. Whenultrasonic sensor US-8 also is OFF, the coil of relay 2-CR isdeenergized and its contacts in branches 81, 82 now open. Thisdeenergizes winding 32a of solenoid valve 32 (FIG. 4) and moves thevalve to the open position illustrated in FIG. 4 and deenergizes winding40a of solenoid valve 40 (FIG. 4) and moves the valve to the openposition illustrated in FIG. 4. Oil pressure is now applied to the leftend of cylinder 46 and nozzle 16 is raised toward the UP position. Assoon as the distance between the car surface and the face of US-8exceeds 12 inches, US-8 turns ON. This energizes the coil of relay 2-CRand its contacts in branches 81, 82 close. This energizes coil 40a andmoves solenoid valve 40 to the closed or blocking position, therebyholding nozzle 16. If the distance between the face of the ultrasonicsensor units and the car surface should exceed 14 inches, ultrasonicsensor US-7 will turn ON. Relay coil 1-CR will now be energized and itscontacts 1-CR in branch 83 will close. This energizes the coil of timerrelay 1-TR and, after a delay of two seconds, the 1-TR contacts inbranch 81 will open. This deenergizes the coil 32a of solenoid valve 32and moves valve 32 to the closed position. However, during thetwo-second delay, the valve 32 was in exhaust condition. This allowedthe oil pressure in lines 45a and 45 to be reduced and allowed thepiston in cylinder 46 to move in a direction to lower nozzle 16.

The action of the proximity detector and control system for the secondand preferred embodiment may be summarized as follows. As the distancefrom the ultrasonic sensors to the car surface decreases, either becausethe car is approaching the units and/or because the top nozzle 16 onwhich the ultrasonic sensors are mounted is dropping downwardly, whenthe distance becomes less than 14 inches, the ultrasonic sensor US-7 isturned OFF. When the distance becomes less than 12 inches, ultrasonicsensor US-8 is turned OFF also. When both ultrasonic sensor US-7 andultrasonic sensor US-8 are turned OFF, the control system raises nozzle16 until the distance exceeds 12 inches. The nozzle 16 is then HELD, butonly so long as the distance does not exceed 14 inches. If the distanceexceeds 14 inches, nozzle 16 is allowed to drop downwardly by gravityuntil the distance is between 12" and 14", at which time the nozzle isheld at this distance. Timer delay relays are used to avoid or reduceoscillatory movement. Top nozzle 16 is maintained by the electrical andair/oil circuitry of FIGS. 4, 5 and 7 within a 12-14 inch range. Aspreviously indicated, this is the distance from the reflecting surfaceof the car to the face of the US-7 and US-8 ultrasonic switches.However, these cells are mounted on the blower-nozzle structureapproximately 6 inches above the orifice of the nozzle 16. Thus, therange in which nozzle 16 is maintained is actually 6-8 inches from thecar.

For the convenience of the reader, Table 3 is presented below. Table 3relates to the top nozzle 16. This Table presents in summary form theaction or condition of the top nozzle 16 under the various conditions ofthe ultrasonic sensors US-7 and US-8.

                  TABLE 3                                                         ______________________________________                                        US-7          US-8   Top Nozzle 16                                            ______________________________________                                        OFF           OFF    Raise                                                    OFF           ON     Hold                                                     ON            ON     Lower                                                    ______________________________________                                    

Table 3 given above does not include photoelectric sensor PE-6. Thissensor controls movement of nozzle 16 in the same way for the secondembodiment as for the first embodiment.

We claim:
 1. Automatic car wash equipment comprising:a forced-air dryerincluding a blower for producing high-velocity air and a nozzle fordirecting said high-velocity air toward vehicles being washed; supportmeans for mounting said forced-air dryer above a path followed by saidvehicles to direct said high-velocity air from said nozzle to top opaqueportions and top transparent portions of said vehicles; drive means formoving said nozzle toward and away from said vehicles; first sensormeans mounted on said nozzle for detecting the proximity of said nozzleto said top opaque portions of said vehicles and for developing firstcontrol signals representative of the proximity of said nozzle to saidtop opaque portions of said vehicles; second sensor means mounted onsaid nozzle for detecting the proximity of said nozzle to said toptransparent portions of said vehicles and for developing second controlsignals representative of the proximity of said nozzle to said toptransparent portions of said vehicles; and control means responsive tosaid first and said second control signals for controlling said drivemeans to maintain said nozzle within a preselected proximity range ofsaid top opaque portions of said vehicles and said top transparentportions of said vehicles.
 2. Automatic car wash equipment according toclaim 1 wherein:(a) said first sensor means include a firstphotoelectric sensor focused at a first distance and a secondphotoelectric sensor focused at a second distance and said proximityrange is defined by the difference between said first and said seconddistances; and (b) said second sensor means include an ultrasoundsensor.
 3. Automatic car wash equipment according to claim 2 furtherincluding third sensor means mounted on said nozzle for detecting theproximity of said nozzle to tailgates of open-bed pick-up trucks and fordeveloping third control signals representative of the proximity of saidnozzle to said tailgates.
 4. Automatic car wash equipment according toclaim 3 wherein said control means are responsive to said third controlsignals for controlling said drive means to move said nozzle to a heightwhich clears said tailgates.
 5. Automatic car wash equipment accordingto claim 4 wherein said third sensor means include a photoelectricsensor.
 6. Automatic car wash equipment according to claim 5 whereinsaid photoelectric sensor of said third sensor means is disposed with asubstantially horizontal orientation.
 7. Automatic car wash equipmentaccording to claim 1 wherein said support means include means forvarying the orientation of said nozzle relative to the vertical as saidnozzle moves between its uppermost and lowermost positions.
 8. Automaticcar wash equipment according to claim 7 wherein the orientation of saidnozzle varies from between 15° to 20° from the vertical when said nozzleis in its lowermost position and 5° to 71/2° from the vertical when saidnozzle is in its uppermost position.
 9. Automatic car wash equipmentaccording to claim 2 wherein said support means include means forvarying the orientation of said nozzle relative to the vertical as saidnozzle moves between its uppermost and lowermost positions. 10.Automatic car wash equipment according to claim 3 wherein said supportmeans include means for varying the orientation of said nozzle relativeto the vertical as said nozzle moves between its uppermost and lowermostpositions.
 11. Automatic car wash equipment according to claim 4 whereinsaid support means include means for varying the orientation of saidnozzle relative to the vertical as said nozzle moves between itsuppermost and lowermost positions.
 12. Automatic car wash equipmentaccording to claim 5 wherein said support means include means forvarying the orientation of said nozzle relative to the vertical as saidnozzle moves between its uppermost and lowermost positions. 13.Automatic car wash equipment according to claim 6 wherein said supportmeans include means for varying the orientation of said nozzle relativeto the vertical as said nozzle moves between its uppermost and lowermostpositions.
 14. Automatic car wash equipment comprising:a forced-airdryer including a blower for producing high-velocity air and a nozzlefor directing said high-velocity air toward vehicles being washed;support means for mounting said forced-air dryer along a path followedby said vehicles to direct said high-velocity air from said nozzle toportions of said vehicles, said support means including means forvarying the orientation of said nozzle relative to the vertical as saidnozzle is moved toward and away from said vehicles; drive means formoving said nozzle toward and away from said vehicles; sensor meansmounted on said nozzle for detecting the proximity of said nozzle tosaid portions of said vehicles and for developing control signalsrepresentative of the proximity of said nozzle to said portions of saidvehicles; control means responsive to said control signals forcontrolling said drive means to maintain said nozzle within apreselected proximity range of said portions of said vehicles; and saidsensor means including a first photoelectric sensor focused at a firstdistance and a second photoelectric sensor focused at a second distanceand said proximity range is defined by the difference between said firstand said second distances.
 15. Automatic car wash equipment comprising:aforced-air dryer including a blower for producing high-velocity air anda nozzle for directing said high-velocity air toward vehicles beingwashed; support means for mounting said forced-air dryer alongside apath followed by said vehicles to direct said high-velocity air fromsaid nozzle to side portions of said vehicles, said support meansincluding means for varying the orientation of said nozzle relative tothe vertical as said nozzle is moved toward and away from said vehicles;drive means for moving said nozzle toward and away from said vehicles;sensor means mounted on said nozzle for detecting the proximity of saidnozzle to said portions of said vehicles and for developing controlsignals representative of the proximity of said nozzle to said sideportions of said vehicles, said sensor means including a firstphotoelectric sensor focused at a first distance and a secondphotoelectric sensor focused at a second distance and said proximityrange is defined by the difference between said first and said seconddistance; and control means responsive to said control signals forcontrolling said drive means to maintain said nozzle within apreselected proximity range of said side portions of said vehicles. 16.Automatic car wash equipment comprising:a forced-air dryer including ablower for producing high-velocity air and a nozzle for directing saidhigh-velocity air toward vehicles being washed; support means formounting said forced-air dryer above a path followed by said vehicles todirect said high-velocity air from said nozzle to top opaque portionsand top transparent portions of said vehicles; drive means for movingsaid nozzle toward and away from said vehicles; first sensor meansmounted on said nozzle for detecting the proximity of said nozzle tosaid top opaque portions of said vehicles and said top transparentportions of said vehicles and for developing first control signalsrepresentative of the proximity of said nozzle to said top opaqueportions of said vehicles and said top transparent portions of saidvehicles; second sensor means mounted on said nozzle for detecting theproximity of said nozzle to tailgates of open-bed pick-up trucks and fordeveloping second control signals representative of the proximity ofsaid nozzle to said tailgates; and control means responsive to saidfirst and said second control signals for controlling said drive means:(1) to maintain said nozzle within a preselected proximity range of saidtop opaque portions of said vehicles and said top transparent portionsof said vehicles and (2) to move said nozzle to a height which clearssaid tailgates.
 17. Automatic car wash equipment according to claim 16wherein said second sensor means include a photoelectric sensor. 18.Automatic car wash equipment according to claim 17 wherein saidphotoelectric sensor of said second sensor means is disposed with asubstantially horizontal orientation.
 19. Automatic car wash equipmentaccording to claim 16 wherein said support means include means forvarying the orientation of said nozzle relative to the vertical as saidnozzle moves between its uppermost and lowermost positions. 20.Automatic car wash equipment according to claim 19 wherein theorientation of said nozzle varies from between 15° to 20° from thevertical when said nozzle is in its lowermost position and 5° to 71/2200 l from the vertical when said nozzle is in its uppermost position. 21.Automatic car wash equipment according to claim 17 wherein said supportmeans include means for varying the orientation of said nozzle relativeto the vertical as said nozzle moves between its uppermost and lowermostpositions.
 22. Automatic car wash equipment according to claim 18wherein said support means include means for varying the orientation ofsaid nozzle relative to the vertical as said nozzle moves between itsuppermost and lowermost positions.
 23. Automatic car wash equipmentaccording to claim 16 wherein said first sensor means include a firstultrasonic sensor set at a first range and a second ultrasonic sensorset at a second range and said proximity range is defined by thedifference between said first and said second ranges.
 24. Automatic carwash equipment according to claim 23 wherein said second sensor meansinclude a photoelectric sensor.
 25. Automatic car wash equipmentaccording to claim 24 wherein said photoelectric sensor of said secondsensor means is disposed with a substantially horizontal orientation.26. Automatic car wash equipment according to claim 25 wherein saidsupport means include means for varying the orientation of said nozzlerelative to the vertical as said nozzle moves between its uppermost andlowermost positions.
 27. Automatic car wash equipment according to claim26 wherein the orientation of said nozzle varies from between 15° to 20°from the vertical when said nozzle is in its lowermost position and 5°to 71/2° from the vertical when said nozzle is in its uppermostposition.
 28. Automatic car wash equipment comprising:a forced-air dryerincluding a blower for producing high-velocity air and a nozzle fordirecting said high-velocity air toward vehicles being washed; supportmeans for mounting said forced-air dryer along a path followed by saidvehicles to direct said high-velocity air from said nozzle to portionsof said vehicles; drive means for moving said nozzle toward and awayfrom said vehicles; sensor means mounted on said nozzle for detectingthe proximity of said nozzle to said portions of said vehicles and fordeveloping control signals representative of the proximity of saidnozzle to said portions of said vehicles; control means responsive tosaid control signals for controlling said drive means to maintain saidnozzle within a preselected proximity range of said portions of saidvehicles; and said support means including means for varying theorientation of said sensor means relative to the vertical as said nozzleis moved toward and away from said vehicles, said orientation of saidsensor means varying between 15° to 20° from vertical when said nozzleis in its lowermost position and 5° to 7.5° from vertical when saidnozzle is in its uppermost position.